.Net 4.5 WPF application worked fine on Windows 7, malfunction on Windows 10 for Chinese characters. Is this expected?

We have .Net 4.5 based WPF application. It works correctly on Windows 7.
When we moved it to Windows 10 it started malfunctioning.
On investigation we found that when we type a set of 2 character typing will make one Chinese character.
In windows 7 when we press first character it is converted to <BLANK space> for display in text box. When we press another character again it decides the final Chinese character to render.

In windows 10 this behaviour has changed.
when we press first character it is NOT converted but render as it is. When we press another character it decides the final Chinese character to render, by replacing first and second character typed.